jscode:

functionbulidform(){

varstore=newext.data.simplestore({

fields:["id","name"],

data:[[1,"item1"],[2,"item2"]]

});

varform=newext.form.formpanel({

id:"_form",

title:"panelforcomboxtest",

width:300,

height:150,

renderto:document.body,

items:[

{

id:"cbitem1",

xtype:"combo",

valuefield:"id",

displayfield:"name",

emptytext:"請選擇",

mode:"local",

value:"",

store:store,

triggeraction:"all",

listeners:{select:function(combox,record,index){

var_com=ext.getcmp("cbitem2");

if(!_com.disabled){

_com.disable();

}

}}

},

newext.form.combobox({

valuefield:"id",

displayfield:"name",

mode:"local",

value:"item1",

store:store,

id:"cbitem2",

triggeraction:"all"

})

]

});

}

ext.onready(bulidform);

ps:emptytext屬性,但下拉框觸發過一次時,便不會再顯示了.